Ge quantum dots light-emitting devices

Abstract

Si photonics becomes one of the research focuses in the field of photonics. Si-based light-emitting devices are one of the most important devices in this field. In this paper, we review the Si-based light-emitting devices fabricated by embedding Ge self-assembled quantum dots into optical microcavities. Ge self-assembled quantum dots emit light in the telecommunication wavelength range from 1.3 to 1.6 μm, for which Si is transparent. Ge self-assembled quantum dots were grown on silicon-on-insulator (SOI) by molecular beam epitaxy (MBE) in Stranski-Krastanov (S-K) mode. Then, electron beam lithography (EBL) was used to define the pattern of optical microcavities on the wafer. Finally, the pattern was transferred onto the Si/Ge slab by inductive coupled plasma (ICP) dry etching. Room-temperature photoluminescence (PL) was used to characterize the light-emitting properties of fabricated devices. The results showed that strong resonant light emission was observed in different optical microcavities. Significant enhancement of the intensity was obtained by the optical resonance. Based on the results of PL, we designed and fabricated current-injected light-emitting devices based on Ge self-assembled quantum dots in optical microcavities. Room-temperature resonant light emission was observed from Ge dots in a 3.8 μm microdisk resonator.

Keywords

Si-based light-emitting devices / Ge self-assembled quantum dots / microcavities / photonic crystal (PhC) / microdisk

References

[1] Nayak D K, Usami N, Fukatsu S, Shiraki Y. Band-edge photoluminescence of SiGe/strained-Si/SiGe type-II quantum wells on Si(100). Applied Physics Letters, 1993, 63(25): 3509-3511

[2] Fukatsu S, Usami N, Kato Y, Sunamura H, Shiraki Y, Oku H, Ohnishi T, Ohmori Y, Okumura K. Gas-source molecular beam epitaxy and luminescence characterization of strained Si_1-xGex/Si quantum wells. Journal of Crystal Growth, 1994, 136(1-4): 315-321

[3] Fukatsu S, Sunamuru H, Shiraki Y, Komiyama S. Phononless radiative recombination of indirect excitons in a Si/Ge type-II quantum dot. Applied Physics Letters, 1997, 71(2): 258-260

[4] Kawaguchi K, Morooka M, Konishi K, Koh S, Shiraki Y. Optical properties of strain-balanced SiGe planar microcavities with Ge dots on Si substrates. Applied Physics Letters, 2002, 81(5): 817-819

[5] Dashiell M W, Denker U, Müller C, Costantini G, Manzano C, Kern K, Schmidt O G. Photoluminescence of ultrasmall Ge quantum dots grown by molecular-beam epitaxy at low temperatures. Applied Physics Letters, 2002, 80(7): 1279-1281

[6] Kim E S, Usami N, Shiraki Y. Control of Ge dots in dimension and position by selective epitaxial growth and their optical properties. Applied Physics Letters, 1998, 72(13): 1617-1619

[7] Lynch S A, Paul D J, Townsend P, Matmon G M, Suet Z, Kelsall R W, Ikonic Z, Harrison P, Zhang J, Noriss D J, Cullis A G, Pidgeon C R, Murzyn P, Murdin B, Bain M, Gamble H S, Zhao M, Ni W X. Toward silicon-based lasers for Terahertz sources. IEEE Journal of Selected Topics in Quantum Electronics, 2006, 2(6): 1570-1577

[8] Dehlinger G, Diehl L, Gennser U, Sigg H, Faist J, Ensslin K, Grützmacher DMüller E. Intersubband electroluminescence from silicon-based quantum cascade structures. Science, 2000, 290(5500): 2277-2280

[9] Franzò G, Priolo F, Coffa S, Polman A, Camera A. Room-temperature electroluminescence from Er-doped crystalline Si. Applied Physics Letters, 1994, 64(17): 2235-2237

[10] Pavesi L, Dal Negro L, Mazzoleni C, Franzò G, Priolo F. Optical gain in silicon nanocrystals. Nature, 2000, 408(6811): 440-444

[11] Ng W L, Lourenço M A, Gwilliam R M, Ledain S, Shao G, Homewood K P. An efficient room-temperature silicon-based light-emitting diode. Nature, 2001, 410(6825): 192-194

[12] Purcell E M. Spontaneous emission probabilities at radio frequencies. Physical Review, 1946, 69: 681

[13] Yablonovitch E. Inhibited spontaneous emission in solid-state physics and electronics. Physical Review Letters, 1987, 58(20): 2059-2062

[14] Kawaguchi K, Koh S, Shiraki Y, Zhang J. Fabrication of strain-balanced Si_0.73Ge_0.27/Si distributed Bragg reflectors on Si substrates. Applied Physics Letters, 2001, 79(4): 476-478

[15] Kawaguchi K, Morooka M, Konishi K, Koh S, Shiraki Y. Optical properties of strain-balanced SiGe planar microcavities with Ge dots on Si substrates. Applied Physics Letters, 2002, 81(5): 817-819

[16] Kawaguchi K, Koh S, Shiraki Y, Zhang J. Fabrication of strain-balanced Si_0.73Ge_0.27/Si-distributed Bragg reflectors on Si substrates for optical device applications. Physica E, Low-Dimensional Systems and Nanostructures, 2002, 13(2-4): 1051-1054

[17] Kawaguchi K, Konishi K, Koh S, Shiraki Y, Kaneko Y, Zhang J. Optical properties of strain-balanced Si_0.73Ge_0.27 planar microcavities on Si substrates. Japanese Journal of Applied Physics, 2002, 41(4B): 2664-2667

[18] McCall S L, Levi A F J, Slusher R E, Pearton S J, Logan R A. Whispering-gallery mode microdisk lasers. Applied Physics Letters, 1992, 60(3): 289-291

[19] Xia J S, Nemoto K, Ikegami Y, Usami N, Shiraki Y. Silicon-based light emitters fabricated by embedding Ge quantum dots in Si microdisks. Applied Physics Letters, 2007, 91(1): 011104

[20] Xia J S, Tominaga R, Usami N, Iwamoto S, Ikegami Y, Nemoto K, Arakawa Y, Shiraki Y. Resonant photoluminescence from Ge self-assembled dots in optical microcavities. Journal of Crystal Growth, 2009, 311(3): 883-887

[21] Xia J S, Ikegami Y, Shiraki Y, Usami N, Nakata Y. Strong resonant luminescence from Ge quantum dots in photonic crystal microcavity at room temperature. Applied Physics Letters, 2006, 89(20): 201102

[22] Xia J S, Ryuichiro T, Fukamizu S, Usami N, Shiraki Y. Generation and wavelength control of resonant luminescence from silicon photonic crystal microcavities with Ge dots. Japanese Journal of Applied Physics, 2009, 48(2): 022102

[23] El Kurdi M, David S, Boucaud P, Kammerer C, Li X, Le Thanh V, Sauvage S, Lourtioz J M. Strong 1.3-1.5 μm luminescence from Ge/Si self-assembled islands in highly confining microcavities on silicon on insulator. Journal of Applied Physics, 2004, 96(2): 997-1000

[24] Boucaud P, Li X, El Kurdi M, David S, Checoury X, Sauvage S, Kammerer C, Cabaret S, Le Thanh V, Bouchier D, Lourtioz J M, Kermarrec O, Campidelli Y, Bensahel D. Ge islands and photonic crystals for Si-based photonics. Optical Materials, 2005, 27(5): 792-798

[25] Li X, Boucaud P, Checoury X, Kermarrec O, Campidelli Y, Bensahel D. Probing photonic crystals on silicon-on-insulator with Ge/Si self-assembled islands as an internal source. Journal of Applied Physics, 2006, 99(2): 023103

[26] Li X, Boucaud P, Checoury X, El Kurdi M, David S, Sauvage S, Yam N, Fossard F, Bouchier D, Fédéli J M, Salomon A, Calvo V, Hadji E. Quality factor control of Si-based two-dimensional photonic crystals with a Bragg mirror. Applied Physics Letters, 2006, 88(9): 091122

[27] El Kurdi M, Checoury X, David S, Ngo T P, Zerounian N, Boucaud P, Kermarrec O, Campidelli Y, Bensahel D. Quality factor of Si-based photonic crystal L3 nanocavities probed with an internal source. Optics Express, 2008, 16(12): 8780-8791

[28] Fukatsu S, Usami N, Chinzei T, Shiraki Y, Nishida A, Nakagawa K. Electroluminescence from strained SiGe/Si quantum well structures grown by solid source Si molecular beam epitaxy. Japanese Journal of Applied Physics, 1992, 31(8A): L1015-L1017

[29] Brunhes T, Boucaud P, Sauvage S, Aniel F, Lourtioz J M, Hernandez C, Campidelli Y, Kermarrec O, Bensahel D, Faini G, Sagnes I. Electroluminescence of Ge/Si self-assembled quantum dots grown by chemical vapor deposition. Applied Physics Letters, 2000, 77(12): 1822-1824

[30] Xia J S, Takeda Y, Usami N, Maruizumi T, Shiraki Y. Room-temperature electroluminescence from Si microdisks with Ge quantum dots. Optics Express, 2010, 18(13): 13945-13950

Acknowledgements

The authors would like to thank Prof. Usami from Tohoku University for his help in the growth of Ge quantum dots. This work was supported by the Fundamental Research Funds for the Central Universities of Huazhong University of Science and Technology (No. 2011TS022) and the National Natural Science Foundation of China (Grant No. 61177049).

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg